Bending press

ABSTRACT

A bending press with hydraulic overhead drive, provided with a vertically reciprocable upper jaw, guided in its reciprocation motion by the machine frame, and which may be inclined with respect to the lower jaw. The upper jaw is operated at least in its lowering direction by a pair of lateral hydraulic thrust cylinders. Between the upper jaw and the piston rod of each thrust cylinder an articulated connection is mounted having its articulation axis at right angles to the plane of the upper jaw, the said articulated connection being in the form of a thrust transmitting support having a cylindrical or spherical shape.

United States Patent [191 Poggio Dec. 10, 1974 [5 BENDING PRESS 3,587,286 6/1971 Fritsch 72/389 [75] Inventor: Sebastiano Poggio, Genova-Borzoli,

Italy Primary ExaminerMilton S. Mehr B l [73] Assignee: Verrina S.P.A., Genoa-Voltri, Italy Attorney Agent or Firm James G 0 0y 6 221 Filed: Sept. 13, 1973 [57] ABSTRACT [21] Appl. No.: 397,024 7 I A bending press with hydraulic overhead drive, provided with a vertically reciprocable upper jaw, guided [30] Forelgn Apphcamm Pnonty Data in its reciprocation motion by the machine frame, and 6, 1972 Italy 12935/72 which may be inclined with respect to the lower jaw.

The upper jaw is operated at least in its lowering di- Cl 5 72/447, rection by a pair of lateral hydraulic thrust cylinders. l00/214 Between the upper jaw and the piston rod of each CL thrust cylinder an articulated Connection is mounted Fleld 0f Search 100/258, having its articulation axis at right angles to the plane 258 A of the upper jaw, the said articulated connection being in the form of a thrust transmitting support having a References cued cylindrical or spherical shape.

UNITED STATES PATENTS Savory 72/456 X 4 Claims, 10 Drawing Figures PATENTEB HEB 10 m4 SEN 3 BF 6 PATENTED DEC 10 I974 SNEETUBF'G PAIENTH) etc a 0mm sum 5 or s BENDING PRESS FIELD OF THE INVENTION This invention relates to a bending press with hydraulic overhead drive, provided with a vertically reciprocable upper jaw which may be inclined with respect to the lower jaw and which is operated at least in its lowering direction by a pair of lateral hydraulic thrust cylinders.

BACKGROUND OF THE INVENTION By the manufacture of profile sheet metal by means of bending presses, it is often necessary to obtain a socalled conical profile, that is a profile in which at least one cross sectional dimension, and for instance the height, is progressively increasing or decreasing in the longitudinal direction of the profile. The said conical profile sheet metal may be obtained in the known bending presses by inclining the upper jaw with respect to the lower jaw. In the known bending presses provided with hydraulic overhead drive, the connection between the upper jaw and the thrust cylinders does not permit to incline to a sufficient degree the upper jaw with respect to the lower jaw, or it does not provide an efficient power transmission from the thrust cylinders to the inclined upper jaw.

SUMMARY OF THE INVENTION It is an object of the invention to provide a bending press of the above mentioned kind, in which it is possible to angularly adjust the upper jaw with respect to the lower jaw in order to manufacture conical profile sheet metal, and in which an efficient power transmission is achieved between the hydraulic thrust cylinders and the inclined upper jaw.

According to the invention the bending press is characterized by the fact that between the upper jaw and the piston rod of each thrust cylinder an articulated connection is mounted, with its hinge axis perpendicular to the plane of the upper jaw, the said articulated connection acting, at least in the lowering direction of the upper jaw, as thrust transmitting bearing between the thrust cylinders and the upper jaw.

According to a further feature of the invention, additional vertical guide means are provided on the machine frame in correspondence of the articulated connections between the upper jaw and the piston rod of each thrust cylinder, for guiding the upper jaw in its vertical reciprocation motion.

Further objects and advantages of the present invention will become more evident from the following specification made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevation ofa bending press according to the invention.

FIG. 2 is a side view of the bending press of FIG. 1.

- FIG. 3 is a cross section ofa first embodiment of the articulated connection between the upper jaw and the piston rod of a thrust cylinder.

FIG. 4 is a top plan view of the articulated connection of FIG. 3.

FIGS. 5 and 6 are longitudinal sections taken along line V-V of FIG. 1 of the articulated connections be- 10 jaw and the piston rod of the corresponding thrust cylinder.

FIGS. 9 and 10 are sections along line IXIX of FIG. 8 of the articulated connections between the upper jaw and the piston rods of the two thrust cylinders.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION Referring to the drawings, 1 is the frame of the bending press. To the lower side of the said frame 1, the stationary lower jaw 2 is secured. A pair of hydraulic thrust cylinders 3 are fastened with their axis vertical to the sides of the upper front of the machine frame 1. The upper jaw 4 is displaceably guided for reciprocation in vertical guides 5 which are fastened on the inwardly directed sides of the two thrust cylinders 3. The upper jaw 4 may be inclined in its vertical plane in the guides 5 with respect to the lower jaw 2. This may be accomplished, in a known manner, by providing for a different stroke of the piston rods 103 of the two cylinders 3. The hydraulic thrust cylinders 3 are double acting hydraulic cylinders controlling both the lowering and the lifting of the upper jaw 4. In correspondence of each thrust cylinder 3 the upper jaw 4 is provided with a lateral portion projecting beneath the corresponding hydraulic cylinder 3, to which the piston rod 103 of the corresponding cylinder 3 is hinge connected.

In the embodiment according to FIGS. 1 to 6, the

said hinge connection between the upper jaw and the piston rod 103 of the cylinders 3 comprises a U-shaped hinge element 6, provided with two downwardly extending legs 106 between which the upper jaw 4 is inserted. The crossbar 206 of the hinge element 6 is connected to the piston rod 103 of the corresponding cylinder 3 in a rotatable manner about the longitudinal axis of the piston rod 3. To this end, the crossbar 206 of the hinge element 6 is provided on its upper side with a circular recess 7, in which the end section of the piston rod 103 is inserted. The piston rod 103 abuts with its rounded head end against the bottom of the recess 7, and is provided with an external anular groove 8, into engagement with a pair of semicircular retaining segments 10, which are bolted by means of bolts 9 to the crossbar 206 of the hinge element 6.

Between the upper jaw 4 and the crossbar 206 of the hinge element 6 a thrust element 11 is housed. The said thrust element 11 is provided with a cylindrically profiled upper side lll abuting against the correspondingly profiled lower side of cross bar 206. The lower side 211 of the thrust element 11 is flat and abuts against a correspondingly flat surface of the upper jaw 4. 1

As shown in FIG. 5, one of the thrust elements 11 is inserted without play into a corresponding recess formed in the upper edge of the upper jaw 4. The second thrust element 11, as shown in FIG. 6, is inserted with a lateral play into a corresponding recess 12 formed in the upper edge of the upper jaw 4.

At a position below the thrust elements 11, the upper jaw is hinged to the hinge elements 6 by means of hinge pins 13, 113, extending through a pair of coaxial borings formed in the legs 106 of the hinge elements 6, and through an axially aligned bore 14, 114 formed in the upper jaw 4. The borings 14, 114 have at least in a vertical direction a dimension which is greater than the diameter of the corresponding pins 13, 113, in order to avoid that, during the operation of the press, the said pins be subjected to a strong compression force.

The hinge pin 13 is guided into the hole 14 of the upper jaw without appreciable horizontal play. The hinge pin 113, on the contrary, is guided into an horizontally oblong hole 114 formed into the upper jaw 4, as best shown in FIG. 6, so as to permit a limited movement in a horizontal direction of the upper jaw with respect to the hinge pin 113. The above feature, in combination with the fact that the corresponding thrust element 11 is mounted with a longitudinal play into the recess 12, permits to incline the upper jaw with respect to the lower jaw, in order to obtain the desired conical profile sheet metal. The inclined adjustment of the upper jaw 4 does not influence the hinge elements 6,

- which are always moving in a vertical direction, that is at right angles to the lower jaw 2. To this end, each hinge element 6 is guided into a vertical guide secured to the machine frame.

According to the embodiment shown in FIGS; 2, 3 and 4, the said slide guides comprises a guide rail 15 cooperating at both sides with two guide flanges 16 of the hinge elements 6, with the interposition of V shaped adjustable gibs 17.

According to the embodiment shown in FIGS. 7 to 10, the thrust elements 11 are mounted directly between the piston rods 103 and the upper support crosspiece 104 of the upper jaw 4.

The upper side 111 of each thrust element 11 has a spherical profile and abuts against the correspondingly profiled lower head surface of the corresponding piston rod 103. The flat lower side 211 of the circular thrust members 11 abut against the flat bottom of a circular recess 12 formed in the upper surface of the crosspiece 104 of the upper jaw 4. The two circular recesses. 12 have a diameter which is greater than the diameter of the thrust elements 11, so that both thrust elements 11 may be adjusted in all horizontal directions with respect to the upper jaw 14.

To the lower end of the piston rod 103 of each thrust cylinder 3, a tie rod 18 is coaxially secured by one end, the said tie rod 18 extending downwardly through a boring 19 of the thrust element 11 and through a boring 20 of the crosspiece 104 of the upper jaw up to an opening 204 formed in the upper jaw 4. To the lower end of the tie rod 18, a spherical articulation head 21 is secured, which is rotatably supported between two lateral support elements 22 projecting inwardly into the opening 204 of the upper jaw. Above the articulation head 21, on the tie rod 18 an engaging element 23 is mounted, into abutment with its upper, spherical surface against a corresponding spherical surface formed in the lower side of the crosspiece 104 of the upperjaw. Between the articulation head 21 and the engaging element 23 a rubber washer 24 is inserted.

The upper jaw 4 is guided along the machine frame 1 in correspondence of its articulated connections with the piston rods 103. To this end, to the machine frame the two rails 15 are secured. On each rail 15 a U- shaped sliding support 25 is mounted, the two legs of each support being into engagement with both sides of the rail 15, with the interposition of V-shaped adjustable gibs 17. The upper jaw 4 is connected in an articulated manner with the crossbar of each sliding support 25 through an horizontal swivel pin 26, disposed at right angles to-the upper jaw plane. Each swivel pin 26 is secured at one end to the corresponding sliding support 25, whilst at its other end it is provided with a head which is into rotatable engagement with ajoint element 27, secured to the upper jaw.

The longitudinal axis of the swivel pin 26 intersects the longitudinal axis of the tie rod 18 at the midle point of the spherical articulation head 21. Between each sliding support 25 and the corresponding joint element 27 secured to the upper jaw 4, a wearing and spacer plate 28 is rotatably mounted on the swivel pin 26. The said wearing and spacing plate 28 is partially housed in corresponding recesses formed in the sliding supports 25 and in the joint elements 27.

In order to incline the upper jaw, same is rotated around the swivel pins 26 with respect to the sliding supports 25 mounted on the steady guide rails 15 secured to the machine frame 1. The requested horizontal adjustment of the upper jaw 4 with respect to the machine frame 1 is permitted by the fact that the guide rail 15 in correspondence of one of the wearing and spacing plate, and for instance the wearing and spacing plate of the right hand cylinder of FIG. 7, is mounted in a larger recess 29 of the corresponding joint element 27, as best shown in FIG. 10. Further, the corresponding swivel pin 26 is guided through a large diameter boring 30 of the joint element 27. Thanks to the above arrangement, the upper jaw together with the joint element secured thereto may be shifted in correspondence of the said cylinder in a horizontal direction with respect to the corresponding sliding support 25 and the swivel pin 26 secured thereto, that is with respect to the wearing and spacing plate 28 which is mounted rotatably but not slidably on the sliding support 25.

I claim:

1. A bending press with hydraulic overhead drive, comprising a frame, a stationery lower jaw secured to said frame, an upper jaw slidably mounted on the said machine frame for a vertical reciprocation motion with respect to the said lower jaw, a pair of lateral hydraulic thrust cylinders secured to the said machine frame and means for operatively connecting the piston rods of the said thrust cylinders to the said upper jaw so as to reciprocate said upper jaw to and from said lower jaw, whilst permitting to incline said upper jaw with respect to the lower jaw, said means comprising a tie rod coaxially secured by one end to the end of the piston rod of each thrust cylinder, a thrust element disposed between the said piston rod and a cross bar integral with and laterally projecting from the upper end of the said upper jaw, the said thrust element and the said cross bar being provided with borings through which the said tie rod is passed with lateral play, a spherical articulation head secured to the lower end of the said tie rod, the said articulation head being supported in a rotatable manner by the upper jaw, and an engaging element coaxial to the said tie rod, disposed above the said articulation head and provided with a curved upper side into abutment with a correspondingly curved surface formed on the lower surface of the cross bar of the upper jaw.

the said upper jaw about a rotation axis which is perpendicular to the upper jaw plane and which passes through the curvature centre of the said articulation heads.

4. A bending press according to claim 3, in which means are provided for shifting at least in a horizontal direction the said upper jaw with respect to the said sliding supports. 

1. A bending press with hydraulic overhead drive, comprising a frame, a stationery lower jaw secured to said frame, an upper jaw slidably mounted on the said machine frame for a vertical reciprocation motion with respect to the said lower jaw, a pair of lateral hydraulic thrust cylinders secured to the said machine frame and means for operatively connecting the piston rods of the said thrust cylinders to the said upper jaw so as to reciprocate said upper jaw to and from said lower jaw, whilst permitting to incline said upper jaw with respect to the lower jaw, said means comprising a tie rod coaxially secured by one end to the end of the piston rod of each thrust cylinder, a thrust element disposed between the said piston rod and a cross bar integral with and laterally projecting from the upper end of the said upper jaw, the said thrust element and the said cross bar being provided with borings through which the said tie rod is passed with lateral play, a spherical articulation head secured to the lower end of the said tie rod, the said articulation head being supported in a rotatable manner by the upper jaw, and an engaging element coaxial to the said tie rod, disposed above the said articulation head and provided with a curved upper side into abutment with a correspondingly curved surface formed on the lower surface of the cross bar of the upper jaw.
 2. A bending press according to claim 1, in which between said engaging elements and the said articulation heads elastic cushion means are interposed.
 3. A bending press according to claim 1, further comprising a pair of vertical sliding guides laterally secured to the machine frame, a sliding support slidably mounted on each of the said vertical sliding guides, and means for connecting in an articulated manner the upper jaw to the said sliding supports in correspondence of the said articulation heads so as to oscillate the said upper jaw about a rotation axis which is perpendicular to the upper jaw plane and which passes through the curvature centre of the said articulation heads.
 4. A bending press according to claim 3, in which means are provided for shifting at least in a horizontal direction the said upper jaw with respect to the said sliding supports. 